Yoshimura Exhaust for 2010-11 YZ450F

[95s10nj]

Not sure if anybody has noticed but yoshimura has seemed to have released an updated exhaust. I recently received my full exhaust and took noticed that it has two mounting points on the muffler where the older ones had one and the silencer is longer and sticks out past the side number plate more. Anybody else notice this? Here's a crappy cell phone pic...

[Davey762]

Sticking out further out the back isnt as nice but not a big deal. Can you take a pic from the inside? Is that the stainless version?

[RJacks]

Is that the RS-4?

[Chazmagnum]

The single tab model was breaking so yes that is the updated 2 tab design.

[95s10nj]

Sticking out further out the back isnt as nice but not a big deal. Can you take a pic from the inside? Is that the stainless version?

Here's a pic off the yosh site that shows it mounted up without the side plate on. Yes that's the stainless version.

Is that the RS-4?

Yes the stainless rs-4 complete system.

[Davey762]

Thanks I checked it out on the yoshimura site as well. It seems that the ti and carbon pipes do not have the double mount however. I have no had an issue with my ti rs4 single mount with about 50 hours on it. The rubber mount is nice and has lots of movement if hit.

[Troutman]

Not sure if anybody has noticed but yoshimura has seemed to have released an updated exhaust. I recently received my full exhaust and took noticed that it has two mounting points on the muffler where the older ones had one and the silencer is longer and sticks out past the side number plate more. Anybody else notice this? Here's a crappy cell phone pic...

Wow that is longer, I would say about 2 to 3 inches longer than my full stainless system. Interesting that I have never seen a post about them breaking yet. I have about 40 hrs on mine with no issues but now I will now keep an eye on it. Do you know if the can is longer of did they just add length to the mid pipe?

[95s10nj]

Thanks I checked it out on the yoshimura site as well. It seems that the ti and carbon pipes do not have the double mount however. I have no had an issue with my ti rs4 single mount with about 50 hours on it. The rubber mount is nice and has lots of movement if hit.

I'm curious as to why it appears to be a few inches longer. I wonder if they found some power advantages to having it longer.

[95s10nj]

Wow that is longer, I would say about 2 to 3 inches longer than my full stainless system. Interesting that I have never seen a post about them breaking yet. I have about 40 hrs on mine with no issues but now I will now keep an eye on it. Do you know if the can is longer of did they just add length to the mid pipe?

Measure your can and I can compare that to the measurement I get. When I ordered mine from yosh they said that it would be a few weeks because they were manufacturing a new line. They indicate that the 2011 model was originally going to be different then the 2010 but then decided to make one part number for the 2010-11. I'll call them tomorrow and ask them whats changed and why.

[95s10nj]

After putting in a call to yosh tech's department, they apparently made the silencer longer to help reduce noise. I definitely prefer the look of the shorter model thats for sure but the exhaust isn't any longer than the stocker so I guess it isnt the end of the world...

[Troutman]

Measure your can and I can compare that to the measurement I get. When I ordered mine from yosh they said that it would be a few weeks because they were manufacturing a new line. They indicate that the 2011 model was originally going to be different then the 2010 but then decided to make one part number for the 2010-11. I'll call them tomorrow and ask them whats changed and why.

My aluminium can section (not carbon end cap or stainless conical section of the can) is 8 inches. Sounds like they lengthend it for noise reasons huh, no big deal the pipe looks sick as is. Well you should love the performance of this pipe it realy frees up the the rev's at top end enjoy ?

[95s10nj]

So I removed the spark arrester today(what a pita). What are you guys doing for inserts? Are you running them without the ring, with the ring or are you using the 99db insert? Is it ok to run it without the insert or the aluminum ring?

[Troutman]

So I removed the spark arrester today(what a pita). What are you guys doing for inserts? Are you running them without the ring, with the ring or are you using the 99db insert? Is it ok to run it without the insert or the aluminum ring?

I removed the screen too and it was a huge PITA!!!! as it sounds like you now know well. I am not sure if it's good to run without any insert so I purchased the open insert. I thought that no insert may not create the appropriate back pressure and have a negative impact on the packing but that is pure speculation. I got the open insert from YOSH it was like $30.

[swaldrop]

So I removed the spark arrester today(what a pita). What are you guys doing for inserts? Are you running them without the ring, with the ring or are you using the 99db insert? Is it ok to run it without the insert or the aluminum ring?

I took the screen out and ran mine without anything for a few motos. The pipe ran good, but sounded awful. I ended up just putting the insert back in minus the screen and now it's great. I would like to try the open insert however just to see how it does, but I have zero complaints as is.

[tristanyamaha16]

I have 2009 yz250f and I was looking at the yoshimura rs4 is it available for my bike?

[todds924]

Thanks I checked it out on the yoshimura site as well. It seems that the ti and carbon pipes do not have the double mount however. I have no had an issue with my ti rs4 single mount with about 50 hours on it. The rubber mount is nice and has lots of movement if hit.

I Like my "shorty" as well...No problems and I've crashed on it a few times. The new "longer" two mount setup was made to be quieter I was told by a guy at Yosh.

[NE14MX]

I run the full stainless FMF system. I tried their 96db insert and it not only really quiets the bike but softens the initial hit. More so than the MXA softer hit tune. Probably great for woods riding but I do tracks and running the Marmot map it was still a little too soft for me. I also tried with no insert and it was loud and I didn't notice any gains between that setup and running the 98db ring. So now I run the 98db ring with the Marmot map. Very happy.

[Chazmagnum]

I have the newest version of the RS4 slip on. I run wide open no insert and I think it sounds awesome! Nice and throaty and not to loud. The power is very snappy and revs much further than stock.